Pulp dehydrator



` April s, 1941. w, E SAXE 2.237.635

PULP DEHYDRATOR Filed July l5, 19159 2 Sheets-Sheet 1 m=1.:..gi'f`l/////////////////////////////////4 HAR/WJ, K/ECH, Fo; TER a HA Rie/6 A TTORL/VEYJ.

April 8, 1941. W. E. SAXE 4 PULP DEHYDRATOR Filed .July A15, 1959 A 2 Sheets-Sheet 2 VENTO/Q, WALTER E. JA XE HARR/J, K/ECH, FOSTER d HARRAS by two metal plates 48 each of which is shaped to present a front or rear wall 49 and a bottom wall 5 0. The walls 50 are inclined downwardly toward their inner adjacent edges between which is secured a collecting trap 5| in which is collected the water removed from the sand, and from which itis conducted by pipes 8| to a reservoir 82. The plates 48 are suitably secured to the under surface of the platform l1 in airsealed relationship therewith, as indicated at 83.

Subatmospheric pressure is maintained in the vacuum chamber 2B by means of a motor driven vacuum pump 52 connected to the vacuum charnber by means of two air pipes 53. The vacuum l pump 52 is equipped with the customary gauge 54. 'I'he degree of vacuum may be regulated by vary ing the speed of a vacuum pump motor 55 or by any other suitable means. The air pipes 53 are connected at their upper ends by a cross air pipe 56 which is perforated to provide communication with the interior -of the vacuum chamberY 28 and which is protected by a hood 51 mounted on and between the end walls 41 for the purpose of protecting the air intake pipe 56 from flying particles of sand or otherV solid or liquid matter.

If desired, exhaust air from the vacuum pump 52 may be conducted to an air chamber (not shown) arranged above and in suitably effected sealing contact with the upper face of the sand bed, and in vertical alignment with the vacuum chamber 20, to provide air at superatmospheric pressure, for the purpose of increasing the velocity of the air through the sand bed.

As will be seen in Fig. 2. the platform |1 is secured to the frame plates'89'. The side walls 28 for retaining' the sand bed laterally are se cured. to and between the platform |1 at their lower edges and horizontal plates 59 at their upper edges, in spaced relationship with the frame walls 39. The plates 59.are rigidly secured to the upper edges of the frame plates 39.

One or more transverse slots or gaps 58 are provided in the platform i1 extending from one side retaining wall 28 to the other side retaining walls 28, over which the sand bed 25 must pass in its travel from the hopper i8 to the chute 22. In the drawings two such gaps 58 are shown. One or more revolving cylindrical brushes 2| are mounted in the vacuum chamber y2 0 between the end walls 41 thereof in bearings-60 secured to the frame plates 39. Each of these brushes corn-v prises' a hub portion 6| and bristles 62- of wire or other stiff material which are mounted in and project radially outward from the hub portion 6|. The outer ends of the bristles 62 constitute a cylindrical surface 8|) which contacts and slides under arcuate flanges 63 depending from the front and rear edges of the transverse gaps 58. The uppermost arcuate portion of the cylindrical surface 80 of each roller occupies one of the gaps 58 and due to its convex lcharacter projects at its center slightly above the horizontal plane of the upper surface of the platform |1.

The brushes 2| are mounted on shafts 84a and 64b which are driven by a sprocket drive as follows. The shaft 64a carries a sprocket 65 which is driven by a sprocket chain 56 i'rom a sprocket wheel 61 on the shaft 31. The shaft 64b is driven from the shaft 64m by means of sprocket wheels 68 and 59 and a sprocket chain 10, The sprocket wheels 51, 55, V69, and 68 are all of the same diameter. As a result, the 'shafts 91, 64a, and 64b revolve at the same speed of rotation. Since also the pitch circle of the drive sprocket 32 is of the same diameter as that of the cylindrical surface 8G described by the outer ends of the bristles 62, the linear speed of the bristle ends is the same as that of the linear speed of the conveyor buckets 80. The sand bed, as it leaves the solid portion of the platform I1 and passes across one of the gaps 58, is received and supported by one of the rollers 2| and is propelled forwardly at the same linear speed as that by which it is moved by the conveyor 29.

` Though preferable, it is not necessary that' the rollers 2| be power driven. If the shafts 64a and 84h are idling shafts, it is obvious that the sand bed, asit moves over the gaps 58, will by reason of its contact with the bristles 62, turn the rollers 2| and the roller shafts 64a and 94h.

Air is drawn downwardly through the sand bed 25, as indicated by arrows 1|, to the gaps 58 and the bristles 62 into the vacuum chamber 20, and thence through the pipes 53 to the vacuum pump 52. Since the bristles 62 converge radially inwardly toward the hub portion or core 6| of the rollers 2|, the particles of sand of the sand pulp are inhibited from being drawn downward through the bristles into the Vacuum chamber. A few particles may become lodged between the outer ends of the bristles. As each roller 2| revolves, bringing suchlodged sand particles into the vacuum chamber, they are dislodged from the bristles by a row of jets of water issuing at high pressure from suitably' shaped perforations in an associated water pipe 12 and fall with the water from the jets into the collecting trap 5|, whence they are led through pipes 8| to the reservoir 82. The water gathered from the sand by the air stream indicated by the arrows 1| also collects in the trap 5| and is led to the reservoir 82.

Tests of a dehydrator embodying my invention have shown that itis not necessary, except with certain sticky materials of low water content, to

-spray the bristles with jets of water in the manner above described. The water extracted' from the sand by the air column moving through the gaps 58, gathers upon the bristles, and when the bristles are pointed downward during their Vreturn movement, this water falls therefrom of the overiiow chute 14 by a supply pipe 15, in

which the flow of water is controlled by a oat valve 18 which is connected to a suitable water i supply, The level 13 is sufllciently below the trap 5I to prevent the water in the reservoir 82 jfrom being drawn upwardly to the vacuum moisture extracted from the sand, and likewise' the percentage of moisture remaining in the sand delivered to thechute 22 may be varied by three different regulatory adjustments. The gate 24 and compacting roller 28 may be moved vertically mately beneath the rims of said gap and to have a return movement at a level below said gap, said means directly contacting the pulp of and supporting said pulp bed across said gap; and means for spraying cleansing fluid on said air-pervious supporting means during said return movement.

'1. In a pulp dehydrator, the combination of a platform support for a moving/pulp bed and having formed therein a gap across which the moving pulp bed is unsupported by said platform and which extends across the path of movement of said pulp bed; means .or moving the pulp bed over said platform; a vacuum chamber below said gap and communicating therewith; and means mounted and operating within said chamber for contactually supporting and moving said pulp bed across said gap substantially in the plane of said platform.

8. In a pulp dehydrator, the combination of:

a platform support for a moving pulp bed and having formed therein a gap across which the moving pulp bed is unsupported by said platform and which extends across the path of movement of said pulp bed: means forl moving the pulp bed over said platform; a vacuum chamber below said gap and communicating therewith; means for supporting and moving the puipbed across said gap substantially in the plane of said plat form; and adjustable means in advance of said gap for establishing any desired constant depth of the pulp bed, comprising a vertically adjustable horizontal compacting roller mounted in vertically spaced relationship with said platform and in advance of said roller, a vertically ade justable horizontally arranged gate mounted in vertically spaced relationship with said platform the range of adjustment of the lower ledge ci said gate being substantially the same as the range of adjustment of said roller.

9. In a pulp dehydrator, the combination of: a platform support for a moving pulp and having formed therein a gap across which the moving pulp bed is unsupported by said platform and which extends across the path of movement of said pulp bed; means for moving the pulp bed over said platform; a vacuum chamber below said gap and communicating therewith; an airpervious supporting means for said pulp bed mounted to move across said gap substantially in the plane of said platform in the direction of travel of the pulp bed and to move proximately.

beneath the rims of said gap, said vmeans directly contacting the pulp of and supporting said pulp bed across said gap; a closed conduit for removing water and particles of pulp from said vacuum chamber; a settling tank at a lower level than said vacuum chamber in which is disposed the lower end of said conduit; means for maintaining a constant water level in said tank above the lower end of said conduit; and means for removingwater laden with said pulp particles from the lower levels of said tank to a conduit suitable for returning said water laden with said particles to said platform.

10. In a pulp dehydrator, the combination of a platform support for a moving pulp 'bed and having formed therein a gap across which the moving pulp bed is unsupported by saidplatform and which extends across the path of movement of said pulp bed; means for moving the pulp bed over said platform; a vacuum chamber below said gap and communicating therewith; a cylindrical brush horizontally rotatably mounted in said vacuum chamber transversely of said platand which extends across the path of said pulp bed; means for moving the pulp bed over said platform; a vacuum chamber below said gap and communicating therewith; and an endless movable supporting means for said pulp disposed in said gap, comprising parallel arranged elongated elements with their upper ends substantially in the plane of said platform and contacting and supporting said pulp, said elements being laterally closely spaced to afford voids for the reception of liquid extracted from the pulp while excluding substantially all particles of the pulp, said supporting means having a return flight, during the movement over vwhich said elements are inverted whereby liquid and any ,particles of pulp removed from the pulp bed may fall therefrom.

l2. In a pulp dehydrator, the combination of: a solid platform provided with at least one air gap therethrough and thereacross; means for feeding a moistened granular material to one end of said platform in a bed; bucket meansfor moving said bed contactually and slidably over said platform from said feeding means; means including a suction box for drawing air through said material and said air gap; and an endless travelling air-pervious conveying means disposed with one portion of its path of travel substantially in the plane of said platform and longitudinally across said gap whereby it directly contacts and supports without relative movement said bed and having its return path in said suction box.

i3. In a pulp dehydrator. the combination of: means for forming a bed of moistened granular material; means for supporting' said bed; means for continuously moving said bed after it is formed, said supporting and moving means causing movement of said bed with its underface describing a surface of smooth contour; means including a suction'chamber having its mouth in and across said surface and interrupting said supporting means: and an air-pervious supporting'means mounted to move longitudinally of said mouth and substantially in said surface and at the speed of travel of said bed.

i4. In a pulp dehydrator, the combination of means for forming a' bed of moistened granular material; means for supporting said bed; means for continuously moving said bed after it is formed, said supporting and moving means causing movement of said bed with its underface describing a surface of mooth contour; means including a suction chamber having its mouth in and across said surface and interrupting said supporting means; and a revolvable brush having radial bristles idly mounted on an axis centrally transverse of said mouth with its upper side substantially in the plane of said surface. whereby the sand-bed rotates said idly mounted brush.

WALTER E. SAXE.

v CERTIFICATE 0F coPzRcToi.` Patent No. 2,257,635.y April a, `1'9LL1.

WALTER E; SAXE. It is herebyd certified that error appears in the printed 'specification of the above numbered pat'eni: requiring correction as follows Page l, sec-v ond column, line 1'?, forr the word "Same" `read seLndl-;y page LL, second column, line 65, claim lli, for "mcoth" read --smooth; and thai'l the seid Letters Patent should be read with this correction therein that the same may conform `to the record of the case in the Patent Office. signed and sealed this 15th day of may, A. D. 19in.

Helrw'y` Van Arsdale,

(Seal) Y Acting Commissioner' of' Patents., 

